Torque release adapter

ABSTRACT

A torque release adapter comprising a receptacle and rigid plate rotatably mounted therein with confronting surfaces normal to the axis of rotation, said surfaces containing recesses in which are mounted bearing members, and means for yieldably applying pressure to the parts to constrain the bearings to said recesses to transmit torque from one part to the other, said yieldable means being yieldable to a torque in excess of a predetermined adjustable amount to permit the parts to separate so that one part rides over the bearing members relative to the other part a distance corresponding to the distance between recesses and then become re-engaged with the bearing members.

[ 51 May 16, 1972 [54] TORQUE RELEASE ADAPTER Lawrence S. Schnepel, 250Goodman Hill Road, Sudbury, Mass. 01776 [22] Filed: Apr. 20, 1970 [21]Appl.No.: 30,043

[72] Inventor:

Related U.S. Application Data [63] Continuation-impart of Ser. No.860,23l, Sept. 23,

I969, abandoned.

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2,733,622 2/l956 Evans ..8l/52 4 FOREIGN PATENTS OR APPLICATIONS 473,2029/1914 France ..l5l/2l C Primary Examiner-James L. Jones, Jr.Attorney-Roberts, Cushman & Grover [5 7] ABSTRACT A torque releaseadapter comprising a receptacle and rigid plate rotatably mountedtherein with confronting surfaces normal to the axis of rotation, saidsurfaces containing recesses in which are mounted bearing members, andmeans for yieldably applying pressure to the parts to constrain thebearings to said recesses to transmit torque from one part to the other,said yieldable means being yieldable to a torque in excess of apredetermined adjustable amount to permit the parts to separate so thatone part rides over the bearing members relative to the other part adistance corresponding to the distance between recesses and then becomere-engaged with the bearing members.

10 Claims, 17 Drawing Figures TORQUE RELEASE ADAPTER This application isa continuation-in-part of application Ser. No. 860,231, filed Sept. 23,1969, now abandoned.

BACKGROUND OF THE INVENTION Torque limiting devices are used for manypurposes, two such devices being shown in US. Pat. Nos. 3,012,456 and3,137,187, in the form of torque wrenches designed to enable limitingthe torque which may be applied in tightening nuts, screws, bolts, andthe like. The purpose is to insure the same degree of tightness for allof the fastening elements applied thereby and/or to prevent itsexceeding the shearing limit of the fastenings. The devices as disclosedin the aforesaid patents are complete implements in and of themselvesand their geometry is such that it is difficult to apply a torqueuniformly, 'to ascertain the point of release and to insure freedom fromapplying a torque in excess of that which it is intended to release.

SUMMARY This invention has for its purpose to provide an adapter whichmay be employed in conjunction with torque multiplying tools, socketwrenches, open end wrenches and the like as mentioned above, to limitthe torque which may be applied; to provide a device which may be set tofunction at a predetermined torque and which may be adjustable toprovide for a range of torques; to provide a device which is small inworking radius and axially short enough to minimize bending coupleswhich tend to reduce efficiency and to be dangerous to the user; toprovide a device which efficiently applies the torque up to the maximumamount for a given adjustment; to provide a device which is free ofexcess overtravel; to provide a device which cannot be manipulated toapply a torque in excess of that for which it is set; and to provide adevice which is light in weight, relatively inexpensive to manufacture,internally resistant to wear, substantially frictionless and whollysealed against damage.

As herein illustrated, the device comprises a receptacle embodying achamber for receiving torque release mechanism, said chamber having aside wall-closed at one end and open at the other, a first shaft fixedto the outer side of the end wall, a second shaft, a rigid disc fixed toone end of the second shaft, said second shaft and disc being mounted inthe receptacle with the disc next to the inner side of the end wall,said disc and end wall providing rigid confronting faces and containinga plurality of regularly spaced recesses located at equal radialdistances from the center, a corresponding number of bearings supportedbetween the disc and end wall in the recesses, and means yieldablyholding the bearings between the disc and end wall comprising aplurality of annular spring members mounted on the second shaft againstthe disc and an annular nut mounted on the second shaft against thespring members, said nut being threaded into the open end of thereceptacle and rotatable therein to adjust the pressure of the springmembers against the disc. In one form of the device the recesses are ofcircular section to receive ball bearings and the portions thereof inone of the confronting surfaces are deeper than those in the other, theportions of greater depth being at least greater than one-half thediameter of the balls. Optionally, the recesses may be of taperingconfiguration with larger ends adjacent the periphery and the smallerends adjacent the center and the bearings in this case arefrusto-conical roller bearings. The means yieldably holding the disc andend wall engaged with the bearings are concave annular spring washersplaced face-to-face. An annular thrust bearing is interposed between theouter side of the rigid disc and the first of the washers, a sleevethrust bearing is mounted in the nut around the second shaft andoptionally there is means for locking the nut in a predeterminedposition of adjustment.

The invention will now be described in greater detail with reference tothe accompanying drawings wherein:

FIG. 1 is an elevation of the torque release adapter;

FIG. 2 is a plan view of FIG. 1 as seen from the top;

FIG. 3 is a plan view of FIG. 1 as seen from the bottom;

FIG. 4 is an elevation of the adapter, partly in section, to much largerscale;

FIG. 5 is an exploded view of the adapter showing the several componentsmaking up the unit, some of which are in elevation or partly inelevation and partly in section and others of which are in section;

FIG. 5a is a view taken on the line 5a-5a of FIG. 5;

FIG. 5b is a view taken on the line 5b-5b of FIG. 5;

FIG. 5c is a view taken on the line 5c-5c of FIG. 5;

FIG. 6 is a view partly in section of an alternative form of closure capfor the unit;

FIG. 6a is a view partly in section of a modification of the cap shownin FIG. 6;

FIG. 6b is a plan view of FIG. 6a;

FIG. 7 is a fragmentary section of the structure designed to operatewith roller bearings in place of ball bearings;

FIG. 7a is a plan view of the roller bearing assembly shown in FIG. 7;

FIG. 8 is an elevation of the adapter provided with a handle to enableeasily placing it in a position for use;

FIG. 9 is a fragmentary vertical section through still another form ofcap;

FIG. 10 is an elevation as seen from the right side of FIG. 9; and

FIG. 1 l is a plan view of FIG. 9.

Referring to the drawings, the torque release adapter comprises areceptacle 10 within which is mounted torque release mechanism 12. Aclosure cap 14 confines the torque release mechanism 12 in thereceptacle and optionally provides for adjustment for the amount of thetorque which will be transmitted by the adapter.

The receptacle 10, as shown in FIG. 4, is of circular crosssectionhaving a cylindrical side wall 15 closed at one end by an end wall 16and open at the other end and providing within the wall a cylindricalchamber 18. The end wall 16 has a portion 20 of reduced diameter andcontains a centrally located opening 24 of non-circular configurationfor receiving a tool or other implement for applying rotation thereto orfor receiving a nut or other fastening to which a turning couple is tobe applied through the adapter. The opening 24 extends through the endwall to the interior of the chamber 18, its axis coinciding with theaxis of the chamber and at its inner end is enlarged diametrically toprovide a shallow circular recess 26. The open end of the receptacle isprovided at its inner side with threads 28. Knurling K (FIG. 1) and/or ahandle H (FIG. 8) may be provided to facilitate placing the adapter inposition for use.

In accordance with the invention the surface 16a of the end wall 16 isprovided with a plurality of recesses 30 arranged in a circle about theaxis of the receptacle close to the wall 15, the recesses beinghemispherical in configuration for receiving ball bearings b. As hereinillustrated, there are twelve such recesses spaced regularly about theaxis of the receptacle.

Within the receptacle there is mounted torque release mechanism 12 whichcomprises a rigid circular disc 32 corresponding substantially indiameter to the inside diameter of the receptacle but enough smaller toturn freely therein, which has in its lower surface 34 a plurality ofrecesses 36 corresponding in a number to the recesses 30. The recesses36 are located at the same radial distance from the axis of the disc andof the receptacle as are the recesses 30 from the axis of thereceptacle. The disc 32 is fixed to one end of a shaft 38 which extendsaxially therefrom through the open end of the receptacle and has areduced portion 40 extending beyond the open end of the receptacle whichis of non-circular cross-section containing a spring-pressed ball 42.The shaft 38 has a shoulder 38a next to the disc on which is mounted anannular roller bearing assembly 44 and provides support outwardly of thebearing for a washer 46 and two pairs of oppositely dished springwashers 48 and 50. The closure cap 14 is in the form of a nut 52provided with externally formed threads 54 for engagement with thethreads 28 at the inner side of the receptacle and is provided with aneck 56 containing diametrically disposed notches 58 for receiving aspanner wrench by means of which it may be turned to screw it into theopen end of the receptacle against the spring washers 44 and 50 and toapply varying degrees of pressure thereto so as to provide for thetransmission of different torques. The closure cap contains a centeropening 60 through which the upper end of the shaft 38 extends and isrotatably supported by a sleeve bearing as- Instead of employing ballbearings b as shown in FIGS.

through 5b, roller bearings r may be employed as shown in FIGS. 7 and7a. The roller bearings r shown are longitudinally conical and thesurfaces 16a, 34 are provided with conical recesses 66 and 68 forreceiving them. The roller hearing assembly 70 for holding the rollerbearings r is shown in FIG. 7a.

Preferably, the recesses 30 or 66 in the surface 16a of the receptacleare made deeper than the recesses 36 or 68 in the surface of the disc 32so that the bearing members remain in the recesses 30, 36 and the disctravels over the bearing members as it rotates relative to thereceptacle, thus the wear is confined for the most part to the surface34 of the disc since the only part that need be made of a hardened steelis the disc or the surface of the disc. The receptacle may be made of amild steel with a material saving in cost.

Modified closure caps are shown in FIGS. 6, 6a and 6b designed to belocked in place after the desired adjustment has been made. The cap 14ashown in FIG. 6 comprises a nut 52a in every respect like that shown inFIGS. 4 and 5, except that it contains a slot 0 part way through itdividing the nut into upper and lower parts 72, 74. A screw 92 isthreaded through a threaded hole 90 in the upper part 72 against thelower part 74 and by forcing the screw against the lower part 74 afterthe nut has been turned to obtain the desired torque release point thenut may be locked at this position.

Optionally, a cap 14b may be employed comprising two rings 72a and 74acontaining openings 76a and 78a through which the shaft 40 extends andwithin which are mounted sleeve bearing assemblies. The upper ring 72ais provided with a neck 56a containing notches 58 by means of which theassembly may be turned to make an adjustment and the lower ring 74a isconnected to the upper ring so as to turn therewith by means ofdiametrically disposed pins 82 having their lower ends fixed in the ring74a and their upper ends slidable in holes in the upper ring. The tworings have external threaded portions 86 and 88 for threaded engagementwith the upper end of the receptacle and the upper ring containsdiametrically disposed threaded holes 90a in which there are mountedscrews 92a. The cap is mounted in the upper end of the receptacle andturned therein until the desired degree of resistance to torque isobtained whereupon the screws 92a are rotated to force the rings awayfrom each other thereby binding their threads 86 and 88 against thethreads 28 at the upper end of the receptacle and thus locking theassembly in place.

A third form of locking cap 140 is shown in FIGS. 8, 9 and 10,comprising an annular nut 100 containing an internal opening 102,external threads 104 and diametrically disposed notches 106-106 toenable turning it in the receptacle. According to this form, holes108-108 are drilled at diametrical positions into the nut from the topside downwardly toward the bottom side but terminating short of thebottom side. These holes 108-108 are started in the top side with theiroutside diameter intersecting the threaded exterior surface of the nutso as to provide openings 110-110 in the threaded surface and extenddownwardly and divergently away from the center of the nut. The openings110-110 in the side accordingly taper from the top to the bottom (FIG.10), increasing in width toward the bottom. The openings -110 expose thethreaded interior of the receptacle 15 to the interior of the holes108-108 and set screws 112-112 are screwed into the holes 108-108 intothreaded engagement with the threads 28 on the. interior of thereceptacle 15. The holes 108-108 themselves have smooth interiorsurfaces and when the set screws 112-112 are drawn down by engagementwith the threads 28 the sloping surfaces of the holes wedge the screwsagainst the threaded interior of the receptacle and hence lock the nutin place. An angle of approximately 6 is suitable for obtaining therequired wedging action and locking of the nut. 4

The adapter is packed with a lubricant and to keep dirt out of theinterior a flat sealing disc 94 (FIGS. 4 and 5) is set into the recess26 and is held therein by a spring 96 disposed between it and a recess98 in the lower side of the plate 32.

If desired the adapter may be calibrated so that by turning the closurecap 14 a predetermined number of turns relative to an index mark thepoint of torque release may be preset.

In operation the adapter will transmit torque applied until the upwardcomponent of force exceeds the spring pressure exerted by the springwashers on the disc which tend to hold it engaged with the bearingmembers whereupon the disc yields upwardly and rides over the bearingmembers relative to the receptacle, the bearing members remaining in therecesses in the receptacle. When the disc has moved a distancecorresponding to the distance between the bearing members it tends toreturn to its undisplaced position. If a torque continues to be appliedwhich exceeds the spring pressure the disc will continue to ride overthe bearing members; however, each time the recesses therein comeopposite the bearing members there will be an audible click indicatingthat the disc is rotating relative to the receptacle and that themaximum torque for which the unit is set has been reached. During therotation the bearing members rotate about their own centers in therecesses in the receptacle. As indicated heretofore the deeper recessesmay be made in the disc rather than the receptacle if desired.

I lclaim: v

1. A torque release adapter comprising a receptacle embodying a chamberfor receiving torque release mechanism, said chamber having a side wallclosed at one end by an end wall and open at the other end, said endwall containing centrally thereof an axially extending opening ofrectangular configuration and at the junction of said rectangularopening and the interior a centrally located circular recess of largercross section than the rectangular opening, saidside wall at the openend containing interior threading, a shaft comprising axially alignedportions of different cross-section and at one end an integral headhaving a flat circular face perpendicular to the axis thereof, saidportions of different cross-section decreasing in area from the portionnext to the head which is the largest toward its distal end andcomprising proximal intermediate and distal portions, said distalportion being of rectangular cross-section, a nut containing a centrallylocated opening adapted to receive the intermediate portion of the shaftwith a clearance therebetween, a sleeve-like needle bearing assemblymounted on the distal portion within the clearance about the shaft, saidassembly being force-fitted into the opening and having an axial lengthcorresponding to the thickness of the nut, said nut having a fiat innerside and a kerfed outer side and being exteriorly threaded peripherallyfor threaded engagement with the interior threading at the open end ofthe wall, said nut being adjustable to support the shaft within thechamber with the head confronting the inner side of the end wall, saidconfronting surface of the head and end wall containing a plurality ofuniformly spaced recesses adapted to receive balls, means yieldablyholding the balls in said recesses comprising spring washers disposed onthe intermediate portion of the shaft between the nut and the head ofthe shaft, antifriction means situated between the head and springwashers comprising a flat annular washer and an annular needle bearingdisposed about the proximal portion of the shaft, said needle bearingbeing confined between the spring washers and the head, said nut sealingthe opening at the open end of the wall, a flat disc mounted in saidcircular recess, and a coiled spring situated between the head and thedisc holding said disc in sealing engagement with the inner end of saidrectangular opening.

2. A torque release adapter according to claim 1, wherein the recessesin the planes of the faces taper, the wider ends being adjacent theperiphery of the faces and the narrower ends adjacent the centers of thefaces, and the bearing members are frusto-conical in shape.

3. A torque release adapter according to claim 1, wherein the nutcomprises concentric parts connected for rotation in unison butseparable in a direction along their common axis of rotation, and screwsthreaded through one part in engagement with the other part by means ofwhich the parts may be forced away from each other to bind theirrespective threads against the threads of the receptacle.

4. A torque release adapter according to claim 1, wherein the nutcontains a slot part way through it parallel to its end faces, athreaded hole through the portion of the nut at one side of the slot anda locking screw threaded into the threaded hole against the portion ofthe screw at the other side of the slot, said locking screw beingadapted by rotation to force the parts at opposite sides of the slotaway from each other thereby to bind the thread on said parts againstthe threads of the receptacle.

5. A torque release adapter according to claim 1, wherein a handle isfixed to said receptacle to extend radially therefrom.

6. A torque release adapter according to claim 1, wherein said annularnut contains diametrically disposed holes entering the top and extendingdownwardly at angles divergent to the axis of the nut, said holes at thetop intersecting the threaded exterior of the nut and providing openingstherein, and a set screw situated in each of the holes in threadedengagement with the threaded interior of the receptacle exposed to theinterior of the hole through said openings.

7. A torque release adapter according to claim 6, wherein the upper endsof the holes are substantially tangent to the pitch circle of thethreaded interior of the receptacle.

8. A torque release adapter according to claim 6, wherein said openingstaper from a minimum width at the top to a greater width at the bottom.

9. A torque release adapter according to claim 6, wherein said holesterminate short of the bottom of the nut.

10. A torque release adapter according to claim 1, wherein said holeshave smooth interior surfaces.

1. A torque release adapter comprising a receptacle embodying a chamberfor receiving torque release mechanism, said chamber having a side wallclosed at one end by an end wall and open at the other end, said endwall containing centrally thereof an axially extending opening ofrectangular configuration and at the junction of said rectangularopening and the interior a centrally located circular recess of largercross-section than the rectangular opening, said side wall at the openend containing interior threading, a shaft comprising axially alignedportions of different cross-section and at one end an integral headhaving a flat circular face perpendicular to the axis thereof, saidportions of different cross-section decreasing in area from the portionnext to the head which is the largest toward its distal end andcomprising proximal intermediate and distal portions, said distalportion being of rectangular cross-section, a nut containing a centrallylocated opening adapted to receive the intermediate portion of the shaftwith a clearance therebetween, a sleeve-like needle bearing assemblymounted on the distal portion within the clearance about the shaft, saidassembly being force-fitted into the opening and having an axial lengthcorresponding to the thickness of the nut, said nut having a flat innerside and a kerfed outer side and being exteriorly threaded peripherallyfor threaded engagement with the interior threading at the open end ofthe wall, said nut being adjustable to support the shaft within thechamber with the head confronting the inner side of the end wall, saidconfronting surface of the head and end wall containing a plurality ofuniformly spaced recesses adapted to receive balls, means yieldablyholding the balls in said recesses comprising spring washers disposed onthe intermediate portion of the shaft between the nut and the head ofthe shaft, antifriction means situated between the head and springwashers comprising a flat annular washer and an annular needle bearingdisposed about the proximal portion of the shaft, said needle bearingbeing confined between the spring washers and the head, said nut sealingthe opening at the open end of the wall, a flat disc mounted in saidcircular recess, and a coiled spring situated between the head and thedisc holding said disc in sealing engagement with the inner end of saidrectangular opening.
 2. A torque release adapter according to claim 1,wherein the recesses in the planes of the faces taper, the wider endsbeing adjacent the periphery of the faces and the narrower ends adjacentthe centers of the faces, and the bearing members are frusto-conical inshape.
 3. A torque release adapter according to claim 1, wherein the nutcomprises concentric parts connected for rotation in unison butseparable in a direction along their common axis of rotation, and screwsthreaded through one part in engagement with the other part by means ofwhich the parts may be forced away from each other to bind theirrespective threads against the threads of the receptacle.
 4. A torquerelease adapter according to claim 1, wherein the nut contains a slotpart way through it parallel to its end faces, a threaded hole throughthe portion of the nut at one side of the slot and a locking screwthreaded into the threaded hole against the portion of the screw at theother side of the slot, said locking screw being adapted by rotation toforce the parts at opposite sides of the slot away from each otherthereby to bind the thread on said parts against the threads of thereceptacle.
 5. A torque release adapter according to claim 1, wherein ahandle is fixed to said Receptacle to extend radially therefrom.
 6. Atorque release adapter according to claim 1, wherein said annular nutcontains diametrically disposed holes entering the top and extendingdownwardly at angles divergent to the axis of the nut, said holes at thetop intersecting the threaded exterior of the nut and providing openingstherein, and a set screw situated in each of the holes in threadedengagement with the threaded interior of the receptacle exposed to theinterior of the hole through said openings.
 7. A torque release adapteraccording to claim 6, wherein the upper ends of the holes aresubstantially tangent to the pitch circle of the threaded interior ofthe receptacle.
 8. A torque release adapter according to claim 6,wherein said openings taper from a minimum width at the top to a greaterwidth at the bottom.
 9. A torque release adapter according to claim 6,wherein said holes terminate short of the bottom of the nut.
 10. Atorque release adapter according to claim 1, wherein said holes havesmooth interior surfaces.